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