I personally think PSU needs to do what they have been doing, and create some turnovers, and give up none.
Your D should be able to keep it somewhat close as long as the O and special teams don't allow Cal great field position.
With Ali being out, and me not knowing your WR's very well this year, it is hard to comment on how your O will do. I'm sure your OL will be up to snuff against Cal...at least for the most part.
I would like to see PSU get an early score one way or another and hold Cal a couple times so it messes with their heads a bit, and they panic a bit. I doubt they will panic, but who knows. Any advantage you can get will be needed, given the disadvantages inherent to playing a I-A team in their house.
Anyway, good luck.