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