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