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