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