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