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