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