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