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