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