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