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