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