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