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