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