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