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