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