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