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