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