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