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