Take a look at the second-last reply on this thread
It includes the harp diagram symbols too, but but those look too unclear for me. So I use Wizzarts’ for the diagrams and the one in the aforementioned link for note names. I create two different paragraph styles: Harp Pedals [15pts rel.] and Harp Pedals Diagram [17 pts. rel.]. I’ve just completed an extensive harp part using this technique. Looks like this:
Hope that helps