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