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