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