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