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