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