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)(25,26,32,36)(27,34,29,30)(28,33,31,35)(37,38,39,40)(1,2)(3,7)(4,5)(6,8)(9,10)(11,17)(12,20)(13,16)(14,19)(15,21)(18,22)(23,24)(25,27,32,29)(26,30,36,34)(28,37,31,39)(33,40,35,38)(2,5)(6,7)(9,10,13,16)(11,17,19,14)(12,15,21,20)(18,23,24,22)(25,28,32,31)(26,33,36,35)(27,37,29,39)(30,40,34,38)(1,2)(3,6)(4,5)(7,8)(9,10)(11,14)(12,15)(13,16)(17,19)(18,22)(20,21)(23,24)(25,29,32,27)(26,34,36,30)(28,37,31,39)(33,40,35,38)(1,2)(3,6)(4,5)(7,8)(9,11,13,19)(10,14,16,17)(12,18,21,24)(15,22,20,23)(25,30,32,34)(26,27,36,29)(28,38,31,40)(33,39,35,37)(1,3,4,8)(2,6,5,7)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(25,31,32,28)(26,35,36,33)(27,37,29,39)(30,40,34,38)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.