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