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