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