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)(25,26,31,34)(27,35,30,32)(28,29,33,39)(36,40,38,37)(1,2,4,5)(3,6,7,8)(9,11,16,13)(10,17,22,19)(12,23,14,21)(15,18,24,20)(25,27,31,30)(26,32,34,35)(28,36,33,38)(29,37,39,40)(9,12,16,14)(10,18,22,20)(11,21,13,23)(15,19,24,17)(25,26,31,34)(27,35,30,32)(28,29,33,39)(36,40,38,37)(1,3,4,7)(2,6,5,8)(9,13,16,11)(10,19,22,17)(12,21,14,23)(15,20,24,18)(25,28,31,33)(26,29,34,39)(27,36,30,38)(32,37,35,40)(9,14,16,12)(10,20,22,18)(11,21,13,23)(15,19,24,17)(25,29)(26,33)(27,37)(28,34)(30,40)(31,39)(32,38)(35,36)(9,15,16,24)(10,21,22,23)(11,18,13,20)(12,19,14,17)(25,30,31,27)(26,32,34,35)(28,38,33,36)(29,37,39,40)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.