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