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