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