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