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