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