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