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