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