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