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