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