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