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