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