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