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