When I went to Enrollment Day, I took the train from East Hills to Glenfield and then to Granville and then it stopped at Kingswood. The problem was after I realised it did take a very long while and I went early (around 9:00am); it took me just over 2 hours I think.
However, I am not going that way anymore. I will be travelling to Central (ahh so easy and the familiarities with the times) and wait for the express InterCity train that goes to Kingswood from one of the Interstate plafforms. It gets you to the campus much, much quicker as it doesn't stop at most stations around 30-45 minutes. Make sure you pick up the Western Line (Emu Plains or Richmond to North Sydney) timetable booklet which is in yellow colour.