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