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