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