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