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)(11,12)(13,17)(14,18)(15,19)(16,23)(20,22)(21,24)(25,26,28,30)(27,33,34,40)(29,37,36,32)(31,38,39,35)(2,5)(6,8)(9,11)(10,12)(13,20)(14,16)(15,21)(17,22)(18,23)(19,24)(26,30)(29,36)(33,40)(35,38) involution — undirected(3,7)(6,8)(9,12)(10,16)(11,17)(13,22)(14,23)(15,24)(18,21)(19,20)(25,27,28,34)(26,31,30,39)(29,38,36,35)(32,40,37,33)(1,3,4,7)(2,6,5,8)(9,13,15,14)(10,17,19,18)(11,20,21,16)(12,22,24,23)(27,34)(31,39)(33,40)(35,38)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.