Green’s Dictionary of Slang

faust n.

[? the fictional Dr Faustus]
(US black)

an ugly person of either sex.

[US]Cab Calloway Hi De Ho 16: Faust: an ugly girl.
[US]Mezzrow & Wolfe Really the Blues 218: Man she’s faust to me, so skip it and fergit it.
[US]S. Longstreet Real Jazz Old and New 148: Faust is not a poem, it means ugly [W&F].

In phrases

like Faust

(US black) in an intensely negative manner.

[US]B. Short Black and White Baby 224: They were down in that dressing room night after night carrying on like Faust.