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