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