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