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