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