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