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