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