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