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