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