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