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