One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,14,22)(7,23,29,65)(8,30,34,59)(9,19,36,61)(10,37,41,57)(11,17,40,54)(12,43,39,48)(13,45,44,21)(15,47,53,25)(16,38,50,31)(18,35,62,42)(20,63,60,24)(26,55,33,51)(27,68,67,49)(28,58,46,56)(32,52,66,64)(1,2)(3,4)(5,7)(6,15)(8,9)(10,32)(11,25)(12,38)(13,46)(14,29)(16,54)(17,50)(18,58)(19,23)(20,30)(21,64)(22,53)(24,27)(26,35)(28,44)(31,39)(33,42)(34,36)(37,68)(40,47)(41,66)(43,51)(45,52)(48,55)(49,57)(56,62)(59,60)(61,65)(63,67) involution — undirected(2,4)(5,8,9,7,24,25,10,38,13,33,35,28,39,66,40,67,14,34,36,29,63,47,41,31,44,26,42,46,12,32,11,27)(6,16,17,53,43,65,18,59,21,49,57,64,60,58,61,51,22,50,54,15,48,23,62,30,45,68,37,52,20,56,19,55)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.