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)(11,17,18,16)(12,21,22,13)(19,20,24,23)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,38)(37,40)(1,3,5,8)(2,6,7,4)(10,15)(11,18)(12,22)(20,23)(25,26,29,32)(27,30,35,33)(28,31,36,38)(34,37,40,39)(1,3)(2,4)(5,8)(6,7)(10,15)(13,21)(16,17)(20,23)(28,36)(31,38)(34,40)(37,39) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,11,14,18)(10,16,15,17)(12,19,22,24)(13,20,21,23)(25,27)(26,30)(28,34)(29,35)(31,37)(32,33)(36,40)(38,39)(9,12)(10,13)(11,19)(14,22)(15,21)(16,20)(17,23)(18,24)(25,26)(27,30)(28,31)(29,32)(33,35)(34,37)(36,38)(39,40) involution — undirected(9,13)(10,12)(11,20)(14,21)(15,22)(16,19)(17,24)(18,23)(25,28)(26,31)(27,34)(29,36)(30,37)(32,38)(33,39)(35,40) 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.