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