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