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