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