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