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