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)(13,14,20,15,19,17,18,22)(16,24,28,25,26,21,27,23)(5,6)(7,11)(8,10)(9,12)(13,15,19,22)(14,18,17,20)(16,25,26,23)(21,28,24,27)(2,4)(5,7,8,12)(6,9,10,11)(13,16,19,26)(14,21,17,24)(15,23,22,25)(18,27,20,28)(7,12)(9,11)(13,17,18,15,19,14,20,22)(16,21,27,25,26,24,28,23)(6,10)(9,11)(14,17)(15,22)(16,26)(27,28) 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.