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