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