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)(20,25)(23,28)(24,29)(27,30)(31,32) involution — undirected(1,3,4,8)(2,5,6,7)(9,10)(11,13)(12,14)(15,16)(17,18,20,22,21,24,25,29)(19,23,27,28,26,31,30,32)(2,6)(3,8)(9,11,12,15)(10,13,14,16)(17,19,21,26)(18,23,24,31)(20,27,25,30)(22,28,29,32)(2,6)(5,7)(10,14)(13,16)(18,24)(19,26)(22,29)(27,30) involution — undirected(2,6)(5,7)(17,18,25,29,21,24,20,22)(19,23,30,32,26,31,27,28)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.