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