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