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