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