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