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