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