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