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