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