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