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