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