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