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)(15,19)(16,25)(17,22)(18,20)(21,24)(23,28)(26,27)(1,2)(3,4)(13,15,18,23)(14,19,20,28)(16,17,24,26)(21,27,25,22)(6,9)(10,11)(14,20)(15,23)(17,26)(21,25) involution — undirected(5,6)(7,10)(8,9)(11,12)(13,14)(15,19)(16,25)(17,22)(18,20)(21,24)(23,28)(26,27) involution — undirected(5,7,8,12)(6,10,9,11)(13,16,18,24)(14,21,20,25)(15,17,23,26)(19,27,28,22)(13,17)(14,22)(15,24)(16,23)(18,26)(19,21)(20,27)(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.