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