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