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