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