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