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