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