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