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