I love Caetano Veloso. And now I hear him sing every time my cell phone rings :) I have the studio version from Putumayo's Acoustic Brazil collection. Sorry that the subtitles in the video below are quite nonsensical, but it's a great live version of the song!
I don't know Portuguese but I understand that cajuína is a beverage distilled from cashew, and that the best cajuína comes from northeastern Brazil. This song refers to Teresina, which may be a place there.
I would welcome a good translation and some information about whether this is a traditional song in Brazil - leave a comment! Also, if it's traditional, is it known in other former Portuguese colonies like Cabo Verde or Angola?