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