One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,9)(4,7)(5,8)(6,11)(10,15)(12,14)(13,16)(17,18)(19,22)(20,24)(21,23)(25,28)(26,29)(27,30)(31,32)(33,34,37,41,38,42,48,54)(35,39,45,51,44,50,57,61)(36,40,47,53,46,52,58,62)(43,49,56,60,55,59,63,64)(1,3)(2,6)(4,10)(5,11)(7,13)(8,9)(12,16)(14,15)(17,19)(18,22)(20,26)(21,25)(23,28)(24,29)(27,31)(30,32)(33,35)(34,39)(36,43)(37,45)(38,44)(40,49)(41,51)(42,50)(46,55)(47,56)(48,57)(52,59)(53,60)(54,61)(58,63)(62,64) involution — undirected(1,4,5,12)(2,7,8,14)(3,10,11,16)(6,13,9,15)(18,23)(19,25)(24,30)(26,31)(33,36)(34,40)(35,43)(37,47)(38,46)(39,49)(41,53)(42,52)(44,55)(45,56)(48,58)(50,59)(51,60)(54,62)(57,63)(61,64)(3,11)(6,9)(10,16)(13,15)(18,23)(22,28)(24,30)(29,32)(36,46)(40,52)(43,55)(47,58)(49,59)(53,62)(56,63)(60,64) involution — undirected(2,8)(6,9)(7,14)(13,15)(17,20,21,27)(18,24,23,30)(19,26,25,31)(22,29,28,32)(35,44)(39,50)(43,55)(45,57)(49,59)(51,61)(56,63)(60,64)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.