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