Something/ someone deemed to be "sexy" is stimulating to the eye/ arousing so verb, "excito" = "rouse up; "wake up"; "raise", "erect"; "arouse" (Oxford) in a present-participle, giving:
"me excitans" = "arousing me".
There are the impersonal verbs: these have only a third-person singular, in each tense and have "it" as their subject e.g. "it is pleasing".
"iuvat" = "it pleases" (+ accusative of the person + infinitive);
"me iuvat eam videre." = "It pleases me to see her.".
"libet" = "it is pleasing" (+ dative + infinitive);
"mihi libuit eam videre." = "It pleased me to see her.".
"placet" = "It pleases" (+ dative);
"mihi placet" = "It pleases me." = "(it is) sexy", would seem to be the best alternative.
EDIT: 2/4/2021:
There are adjectives: "sexualis" = "sexual" & "naturalis" = "sexual" (Oxford) and = "of or pertaining to somebody's nature or qualities" (Wiki).