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)(11,23)(12,27)(13,18)(14,20)(15,21)(16,33)(17,22)(19,25)(24,38)(26,36)(28,37)(29,40)(30,35)(31,39)(32,34) involution — undirected(2,5)(6,8)(9,11)(10,18)(12,14)(13,15)(16,26)(17,28)(19,38)(20,40)(21,23)(22,36)(24,30)(25,31)(27,34)(29,32)(33,37)(35,39) involution — undirected(1,3,4,7)(2,6,5,8)(9,12)(10,19)(11,24)(13,31)(14,28)(15,29)(16,30)(17,25)(18,34)(20,23)(21,35)(22,40)(26,32)(27,33)(36,38)(37,39)(9,13,15,11)(10,18,21,23)(12,14,29,32)(16,28,17,26)(19,39,35,38)(20,40,34,27)(22,36,33,37)(24,25,31,30)(9,14)(10,20)(11,25)(12,28)(13,30)(15,32)(16,31)(17,24)(18,35)(19,23)(21,34)(22,38)(26,29)(27,37)(33,39)(36,40) 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.