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