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