I would reply to tchrist that homo- in "homosexual" is indeed a root meaning "same", but not a Latin one. It is a Greek root illogically attached to a latin noun. Homo, hominis DOES mean "man" in Latin, not "same" – see Homo Erectus, Homo Sapiens, etc.
However, not having the required 50 points, I cannot reply directly.
To answer the question, Ad Feminam is correct if you want top be specific as to the gender of the person to which one refers to. However, as was mentioned before, Homo also takes the general meaning of mankind, as it still does to some extent in modern languages – like in the expression "manslaughter"in English, or in the French "Déclaration Internationale des Droits de l’Homme", instead of the more contemporaneously PC "Déclaration Internationale des Droits des Humains"), etc.
Anyway, I believe more or less everything I said was already mentioned before. But I just wanteds to add my cherry onto to the Homo cake.
Topical humour! Yay!