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