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