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