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)(11,19)(12,22)(13,16)(14,17)(15,18)(20,21)(23,24)(25,26,31,33)(27,32,37,40)(28,34,38,39)(29,35,36,30)(1,3,5,8)(2,6,7,4)(9,11,15,13)(10,16,18,19)(12,20,17,23)(14,21,22,24)(25,27,31,37)(26,32,33,40)(28,36,38,29)(30,39,35,34)(1,3)(2,4)(5,8)(6,7)(12,17)(14,22)(20,23)(21,24)(26,33)(27,37)(28,38)(30,35) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,12,15,17)(10,14,18,22)(11,20,13,23)(16,21,19,24)(25,28)(26,34)(27,36)(29,37)(30,32)(31,38)(33,39)(35,40)(9,13,15,11)(10,16,18,19)(12,20,17,23)(14,24,22,21)(25,29,31,36)(26,35,33,30)(27,38,37,28)(32,39,40,34)(9,14)(10,17)(11,21)(12,18)(13,24)(15,22)(16,23)(19,20)(25,30,31,35)(26,36,33,29)(27,39,37,34)(28,32,38,40)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.