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