One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(18,22)(20,24)(23,28)(25,29)(27,31)(30,32) involution — undirected(1,3,4,8)(2,5,6,7)(9,10)(11,13)(12,14)(15,16)(17,18,20,22,21,25,24,29)(19,23,27,28,26,30,31,32)(2,6)(3,8)(9,11,12,15)(10,13,14,16)(17,19,21,26)(18,23,25,30)(20,27,24,31)(22,28,29,32)(2,6)(5,7)(10,14)(13,16)(19,26)(23,30)(27,31)(28,32) involution — undirected(2,6)(5,7)(17,18,24,29,21,25,20,22)(19,23,31,32,26,30,27,28)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.