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