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