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