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