What to do on the siding around a cable going into the house
Wow, he didn't really care much about craftsmanship. No drip loop sucks; see if there is any slack where you could pull it down a bit into a gentle loop and use a zip-tie to hold the shape (don't kink it). Really all I can see you doing is globbing silicone sealant around it; use the paintable type and maybe you could make it look a bit better by painting the glob once it has cured.

They make split wall bushings you could use to dress it but you would still need the glob of silicone to prevent water intrusion.