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