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