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