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