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