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