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