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