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