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