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