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