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