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