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