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