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