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