One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,8,6,7,5,3)(9,10)(11,18)(12,16)(13,22)(14,17)(15,19)(20,23)(21,24)(25,26)(27,34,36,40)(28,32)(29,38)(30,33)(31,35,39,37)(1,3,5,7,6,8,4,2)(9,11)(10,15,17,24)(12,21)(13,19)(14,20)(16,18,22,23)(25,27,29,37,30,36,28,35)(26,31,32,34,33,39,38,40)(2,7)(3,8)(9,12,14,13)(10,16,17,22)(11,19,20,21)(15,23,24,18)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.