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