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