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