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