Should I show him I'm interested or not.?

If you think you like him, go for it! People do not have to have everything in common to have a good relationship. I mean, haven't you ever heard the phrase "opposites attract?" It's really true. If you think there might be a chance for the two of you to hit it off then start talking to him a little bit more. Make small talk. Nothing drastic at first. Maybe you could start by saying hi, how are you doing? Smile at him when you see him. Flirt a little just so he knows you're interested. Maybe he likes you, but is unsure if you feel the same about him. I hope it works out for the two of you. Goodluck!