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