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