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