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