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