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