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