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