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