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