One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,14)(12,15)(13,16) involution — undirected(1,3,4,8)(2,5,6,7)(9,11,13,12)(10,14,16,15)(17,18,21,25)(19,23,26,31)(20,22,28,24)(27,29,32,30)(9,11,13,12)(10,15,16,14)(18,22)(20,28)(23,29)(24,25)(27,32)(30,31)(2,6)(5,7)(17,19)(18,23)(20,27)(21,26)(22,29)(24,30)(25,31)(28,32) involution — undirected(3,8)(5,7)(9,12,13,11)(10,15,16,14)(18,22)(19,26)(20,28)(23,30)(24,25)(29,31)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.