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