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