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