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