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