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