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