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