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