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