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