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