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