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