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