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