Can co-first authors’ positions be swapped in a CV?
No.  The reference is the reference, changing it to move yourself higher could be misinterpreted as willful deceit.

Add a parenthetical statement at the end of the references saying "first n authors are co-first authors, listed in this order because..."

On my "internal" CV I have parentheticals after many papers, for example, listing contributions, nominations for best paper, etc.