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