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