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