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