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