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