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