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