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