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