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