What are these faint streaks on the moon?

i would rather call the streaks you are referring to as ridges.

the surface of the moon is ofcourse not a perfect sphere and the same way the earth had ups and downs, there are ridges on the moon too.

you say that most of them are diagonal - top-left to bottom-right but on the right hand corner of the image, there are ones vertical ones. So, there is no specific orientation for these "streaks".

on the other hand, if there were streaks around a crater such that concave part of the streaks point towards the crater, they are due to shock waves travelling outwards from the point of impact.