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