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