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