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