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