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