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