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