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