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