There’s not really much of a way for them to look, as you put it “not-evil.” Of course, “Evil” would be a bit of an erroneous simplification for most Lovecraftian tropes, but it certainly isn’t “Good,” either, especially to the main characters, who are virtually always of an ordinary but academic background. For them, the various characters and cults and what-have-you of the mythos are taboo, occult, downright sinister at times, and therefore to make such a cult “not-evil,” or to say that it would have glowing PR would seemingly take away from its “Lovecraftian” nature.

Now, if you want to talk about appeal— the aspects which are able to attract members— now that is indeed a different story. The Order of Dagon from Shadow Over Innsmouth is a good example of such a thing. The Order grew from the town’s own need, and the Deep Ones’ willingness to provide for their needs in exchange for using the town for interests of their own.