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)(11,15)(12,17)(13,22)(14,18)(16,19)(20,24)(21,23)(25,26,29,33,30,34,27,31)(28,36,37,32,38,39,35,40)(1,3)(2,5)(4,8)(6,7)(9,11,14,20)(10,15,18,24)(12,21,13,19)(16,17,23,22)(25,27,30,29)(26,31,34,33)(28,37,38,35)(32,39,40,36)(3,8)(5,7)(9,11)(10,16)(12,19)(13,21)(14,20)(15,22)(17,24)(18,23)(25,28)(26,32)(27,35)(29,37)(30,38)(31,36)(33,39)(34,40) involution — undirected(2,6)(5,7)(9,12,14,13)(10,17,18,22)(11,19,20,21)(15,16,24,23)(25,27,30,29)(26,31,34,33)(28,37,38,35)(32,39,40,36)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.