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