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