Regular expression for a palindrome of finite length?

I have a language $ $ L = \{ww^R, w \in \{ab\}^5\}$ $

I know this is a regular language because it is finite (since w can only be of length 5). I want to prove it’s a regular language, so I’d create a regular expression for it.

Theoretically, my regular expression could be the union of all strings in the language, but is there a concise way to express this rather than writing all possible strings out?