> Can you point out the places where Sirius is being shown prominently in this temple (or any other temple)?

One of the most important rooms in the temple is the Wabet (other names: purification chapel, Uadet):
[commons.wikimedia.org]

It is special due to:
* only room with separate patio room in front
* only room with open sky window in the ceiling (in the patio room)
* only room which is raised from the floor by some steps

The whole square shaped ceiling of this room is showing a shortened version of Nut arching the sky, "giving birth to the sun" (i.e. those strange sun rays made from triangles).
It is considered to be the room which was used during the Egyptian new year

The Egyptian new year was the heliacal rising of Sirius. That happens during the time when the sun was in front of the constellation of Cancer, a few days before the yearly Nile flood starts. That topic is depicted in a larger Nut ceiling relief in the temple entry hall (Hypostyle). Discussion about that is going on in [www.maatforum.com] .

J.A.West also talks about the New Year and Sirius in the following video showing his walk through the temple and Wabet room in 2015:
(start at minute 23) [www.youtube.com]

The importance of Sirius was most likely only known to a small group of royal (Pharaonic) astronomers, to keep it as trade secret.