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)(17,18)(19,23)(20,24)(21,22)(25,26,29,30)(27,33,35,31)(28,32,36,37)(34,39,40,38)(1,3,6,4)(2,7,8,5)(18,21)(19,24)(26,30)(28,36)(31,33)(34,40)(1,3,6,4)(2,5,8,7)(9,10,13,12)(11,14,15,16)(17,19,22,24)(18,23,21,20)(25,27,29,35)(26,31,30,33)(28,34,36,40)(32,38,37,39)(1,4,6,3)(2,7,8,5)(9,11)(10,14)(12,16)(13,15)(17,20)(18,19)(21,24)(22,23)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(1,5,6,7)(2,3,8,4)(9,12,13,10)(11,16,15,14)(17,21,22,18)(19,20,24,23)(25,28)(26,32)(27,34)(29,36)(30,37)(31,38)(33,39)(35,40)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.