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)(13,14,17,21,18,22,23,26)(15,19,16,20,24,27,25,28)(1,2)(3,4)(13,15)(14,19)(16,17)(18,24)(20,21)(22,27)(23,25)(26,28) involution — undirected(6,9)(10,12)(13,16)(14,20)(15,23)(17,24)(18,25)(19,26)(21,27)(22,28) involution — undirected(2,4) involution — undirected(5,7,8,11)(6,10,9,12)(15,24)(16,25)(19,27)(20,28)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.