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