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