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