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