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)(15,20)(16,21)(19,22)(23,24)(25,26,29,33)(27,31,34,30)(28,36,37,32)(35,38,40,39)(3,7)(6,8)(10,11)(15,17)(16,18)(22,23)(27,34)(30,31)(35,40)(38,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(10,11)(15,17)(16,18)(22,23)(25,27,29,34)(26,30,33,31)(28,35,37,40)(32,38,36,39)(1,3)(2,6)(4,7)(5,8)(9,11,14,10)(12,15,20,17)(13,18,21,16)(19,22,24,23)(25,27)(26,31)(28,35)(29,34)(30,33)(32,39)(36,38)(37,40)(1,2)(3,6)(4,5)(7,8)(9,12,14,20)(10,15,11,17)(13,19,21,24)(16,22,18,23)(25,26)(27,30)(28,32)(29,33)(31,34)(35,38)(36,37)(39,40)(9,13)(10,16)(11,18)(12,19)(14,21)(15,22)(17,23)(20,24)(25,28,29,37)(26,32,33,36)(27,35,34,40)(30,38,31,39)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.