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