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)(13,14,18,21)(15,22,23,28)(16,20,17,25)(19,26,27,24)(5,6)(7,11)(8,10)(9,12)(13,15,18,23)(14,19,21,27)(16,24,17,26)(20,28,25,22)(2,4)(5,7,8,12)(6,9,10,11)(13,14)(15,19)(16,25)(17,20)(18,21)(22,24)(23,27)(26,28)(7,12)(9,11)(13,16)(14,20)(17,18)(19,27)(21,25)(24,26) involution — undirected(6,10)(9,11)(15,23)(19,27)(22,28)(24,26) 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.