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