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