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