How do I keep a cat out of my garage?

So there’s been this cat that’s been in and out of our garage for about a week now. It isn’t a problem to me, really, but my dad has declared a holy war against it. At one point, it wound up inside the house, sleeping in a cabinet in the laundry room overnight. It apparently lingers somewhere near the house, because within the span of about 15 minutes of the garage door being open last morning, it sneaked back in and hid behind a toolchest before we chased it back out (Rather, my dad, who began jumping and banging the largest things he could find and yelling as loud as he could like a f***ing madman). I saw it on the porch coming back home from school today, and I chased it off. My dad found that between now and last morning, the cat had knocked over the crushed cans and left a present in the garage again; I suspect it was like that this morning, because the garage doors were closed all day, but of course my dad thought it teleported magically in.

So what do we need to do to keep it out? It has no collar so we assume it’s a stray.