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