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