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