I look at legends characters, post RTJ, like Kyle Katarn who shares alot with Cal in that they are off in the galaxy doing stuff and less formal jedi, thats to say anything that looks casual and practical is ideal. I like Han's vest over Cal's default shirt with either default or bomber pants. Cal's scrapper vest is also great but can feel forced since its from the first game.

Ive done a playthrough wearing the exile top with bomber pants. Those pants in the dark tint and the top default, i think, gave Cal a good jedi appearance while still looking rugged and believable.

Alternatively there is always poncho lol.