The Apis Bull is connected to Khufu’s Vizier Hemiunu through his titles, one of which is "[3] Staff of Apis, Staff of the White Bull, who loves his lord" (refer to Global Egyptian Museum). According to Simpson:

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Simpson
On the sealing King Dn (also read Wdi-mw, Ny-wdiw etc.) is represented wearing the Lower Egyptian crown and running before the Apis bull, apparently in the ceremony elsewhere known as phrr Hp “the running of the Apis”. The meaning of this scene and the corresponding scene with the king wearing the Upper Egyptian crown has been discussed by Blackman, Kees and others in relation to the Sed Festival.

Thus we have a connection between Apis and the Sed Festival. The Sed festival, according to Petrie is not a regnal year festival, but is held on a regular cycle of thirty years to an astronomical cycle. While Petrie aligns the sed festival to an astronomical cycle, he does not propose which cycle. Petrie offers the following explanation for the Sed festival being thought of as a regnal feast:

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Petrie
Though the vanity of Ramessu II. Led to his transferring the astronomical cycle of 30 years to his personal reign and starting a series of Sed festivals on his 30th year, and even repeating them every 3 years after that, such a perversion does not affect the value of the regular cycle for historical purposes.

Kelley and Milone propose a linkage between Saturn and the Sed Festival based on the name of the 29th day of the lunar month:

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“The names of the days of the lunar month (given in Table 8.2) include the 26th day, Peret and “going-forth,” “emergence,” and normally interpreted as “heliacal rise” with reference to Sirius may refer to the 26th year as the beginning of a lunar cycle. If this is accepted, then the reference to the 29th day as “Peret Min” may refer to the 29-year sidereal period of Saturn and would identify the ithyphallic Min as one aspect of Saturn, perhaps relating Saturn to the Sed festival."

Depuydt relays Herodotus telling the story of Cambyses slaying the Apis Bull calf in a fit of rage. When Cambyses queried why the Egyptians were celebrating when he had suffered the misfortune of losing most of his army, we are informed:

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Depuydt
“The Egyptians told him that their god was wont to appear only at very long intervals of time and that, whenever he did so appear, all the Egyptians rejoiced and kept festival”

This story while not specifically mentioning the Sed festival links the Apis Bull to a deity that appears only at very long intervals of time. I now turn to the markings that were required, at least partially in order for a calf to be declared the new Apis Bull. According to Mark, the Apis Bull:

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Mark
had to be black with a white triangular marking on its forehead, another white marking on its back in the shape of a hawk's or vulture's wings, a white crescent on its side, a separation of the hairs at the end of its tail, (known as the "double hairs") and a lump under its tongue in the shape of a scarab.

Starting with the white triangular marking on the forehead, there may be a linkage to the design theme of the Great Pyramid as it was originally encased in white Tura limestone casing blocks. Moving beyond the triangular marking, according to Quack, Saturn was known as “Horus, bull of the sky”. Quack presents images from the Temple of Dendera of Saturn, one of which is a human form with a black bulls head, the other is a bird, presumably a hawk with a white or tan bulls head. This raises the possibility that the hawk or vulture’s wings marking on the Apis Bull’s back is a reference to Horus, Bull of the Sky, or Saturn.

Quack also tells us of a possible attestation of Saturn “In the Pyramid Texts and the Coffin Texts, a “bull of heaven” is mentioned several times. Already Brugsch had supposed that this could be understood as the planet Saturn”. The “bull of heaven” appears in connection with the Apis Bull in the Pyramid Texts:

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279: The two ridges of the mountain (on both sides of the Nile valley) shall be united.
The two banks of the river will be joined.
The roads will be hidden from the passers-by.
The steps (rwd.w) will be annihilated for those who go up.
Make tight the rope (of the boat), sail the road of heaven!
Strike the ball on the meadow of Hapi (Apis)!

280: Ha! Your fields are in fright, o jAd-star,
before the pillar of stars,
when they have seen the pillar of Kenset (a country), the Bull of Heaven.
How the herdsman of the bulls is overwhelmed with awe before him!

Returning to the Sed festival, of which the running of the Apis Bull is linked, the Khufu Pyramid complex is linked to the Sed festival by Hawass where he views the Satellite Pyramid (G1d) as linked:

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“The scenes of the sed festival occur on the walls of the southern tomb, which is a prototype of the Satellite Pyramid. The scenes also occur in the wall reliefs of the Pyramid Complexes from Dynasties IV to VI of the Old Kingdom. Therefore it is proper to suggest that there is a connection between the sed festival and the Satellite Pyramid.”

In summary, there is a set of linkages from Khufu to his Vizier Hemiunu, a staff of the Apis Bull according to his titles which brings the Apis Bull into focus. The Apis Bull is linked to the Sed Festival through the running of the Apis Bull. The Sed Festival is believed by Petrie to be an astronomical rather than regnal feast on a regular 30 year cycle. While Petrie does not specify Saturn, Saturn is represented as a Bull and has an approximate 29.5 year orbital cycle. The Sed Festival is also linked to the pyramid complex by Hawass. Thus, there is good reason we may find a design influence arising from observation of Saturn in the Great Pyramid.

References

Depuydt, L., Murder in Memphis: The Story of Cambyses's Mortal Wounding of the Apis Bull (Ca. 523 B. C. E.), Journal of Near Eastern Studies, Vol. 54, No. 2 (Apr., 1995), pp. 119-126
Global Egyptian Museum, Hemiunu, accessed from [www.globalegyptianmuseum.org]
Hawass, Z., The Discovery of the Pyramidion of the Satellite Pyramid of Khufu G1D
with an Appendix by Josef Dorner, VariaAegyptiaca 1012-3(1995)
Mark, J., Apis, accessed from [www.ancient.eu]
Petrie, WMF, A History Of Egypt During The Xviith And Xviiith Dynasties, Third Edition, 1899, Methuen And Co, p33
Quack, J., The Planets in Ancient Egypt, accessed from [oxfordre.com]
Simpson, W., A Running of the Apis in the Reign of ‘Aha and Passages in Manetho and Aelian, Orientalia, Vol. 26, No. 2, 1957 pp. 139-142