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