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