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