If you can actually make Sokar out from the darkness he routinely lives in, or manage to catch him when he's merging forms with Ptah and/or Osiris, you might be able to see what Sokar looks like. Otherwise, he's just the darkness, like we already told you.
Build: well built
Complexion: red-brown (in human form), silver (in hawk-headed form)
Hair Color: a black or lapis blue wig, if shown (in either form)
Facial Hair: a long black or lapis blue beard (in human form)
Jewelry and accessories: a gold collar, bracelets, and a royal scepter in (living) human form. As Osiris-Sokar, he's a mummy wearing Osiris's white crown.
Clothing: a white linen kilt in human form; as a mummy, he wears white bandages from his toes to his neck
Armor: a golden scale mail shirt in human (non-mummy) form as Ptah-Sokar-Osiris
Type of Weapon: death is its own weapon
Anubis, Osiris, Ptah, Nephthys, dead people and underworld spirits
Burger King (tasty onion rings!)
Black metal concerts
Inside your shadow