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