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