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)(11,15)(12,14)(13,20)(16,21)(17,18)(19,24)(22,23)(28,36)(32,37)(34,40)(38,39)(1,3,4,8)(2,5,6,7)(9,11,14,17)(10,15,12,18)(13,19,21,23)(16,22,20,24)(25,26)(27,33)(28,32)(29,30)(31,35)(34,39)(36,37)(38,40)(10,12)(11,17)(16,20)(19,23)(26,30)(31,33)(32,37)(38,39) involution — undirected(9,11)(10,15)(12,18)(13,19)(14,17)(16,22)(20,24)(21,23)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39) involution — undirected(9,12,14,10)(11,18,17,15)(13,20,21,16)(19,24,23,22)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(9,13)(10,16)(11,19)(12,20)(14,21)(15,22)(17,23)(18,24)(25,28)(26,32)(27,34)(29,36)(30,37)(31,38)(33,39)(35,40) 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.