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