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)(11,13,17,22)(12,19,21,16)(18,24,23,20)(25,26,29,30)(27,33,35,31)(28,32,36,37)(34,39,40,38)(1,3,5,8)(2,6,7,4)(9,10,14,15)(11,13,17,22)(12,16,21,19)(18,20,23,24)(26,30)(31,33)(32,37)(38,39)(1,3)(2,4)(5,8)(6,7)(10,15)(13,22)(16,19)(20,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40) involution — undirected(1,4)(2,3)(5,6)(7,8)(9,11,14,17)(10,13,15,22)(12,18,21,23)(16,20,19,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(9,12,14,21)(10,16,15,19)(11,18,17,23)(13,20,22,24)(25,27,29,35)(26,31,30,33)(28,34,36,40)(32,38,37,39)(9,13)(10,17)(11,15)(12,20)(14,22)(16,23)(18,19)(21,24)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)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.