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