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