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