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