If you really look, festae and Mayans are really not look alikes any more than any Amphilophine or or other cichlids that make their living in the same manner (feeding preferences etc).
Below a female festae.
Note the caudal blotch (@ in the upper half of the caudal), which is common in many South American cichlids, as opposed to the caudal blotch in most Central Americans which covers the middle part of the caudal See in the euro photos others have posted.
Below a male festae.