The expression "to dig" something comes from 1970's American slang. Can you dig it? means "Do you relate to this, and understand it? To say, "I really dig the group Can of Heat," means that you really like a certain rock group. I don't dig it when my Dad gets drunk at parties, means that it embarrasses you to see your father intoxicated in public. So, to "dig it the most" means that someone thinks you would really really be into something they know about.

To dig something means to like something, so yes you're right. It literally means to 'like' it the most