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