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