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