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