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