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