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)(11,19)(12,21)(13,23)(14,15)(16,20)(17,22)(18,24)(25,26,30,31)(27,28,35,32)(29,33,37,38)(34,36,40,39)(2,7)(3,8)(10,15)(13,24)(16,19)(17,21)(26,31)(28,32)(29,37)(34,40) involution — undirected(1,3,6,8)(2,4,7,5)(10,15)(11,20)(17,21)(18,23)(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)(10,16)(12,18)(13,21)(14,20)(15,19)(17,24)(22,23)(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)(10,17)(11,18)(13,19)(14,22)(15,21)(16,24)(20,23)(25,28,30,32)(26,27,31,35)(29,36,37,39)(33,34,38,40)(1,5,6,4)(2,8,7,3)(9,13,14,24)(10,18,15,23)(11,21,20,17)(12,19,22,16)(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.