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