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)(13,14,17,21,18,22,15,19)(16,20,25,28,26,24,23,27)(1,2)(3,4)(5,6)(7,11)(8,10)(9,12)(13,15,18,17)(14,19,22,21)(16,23,26,25)(20,27,24,28)(5,7,8,12)(6,9,10,11)(13,14)(15,21)(16,24)(17,19)(18,22)(20,26)(23,27)(25,28)(2,4)(7,12)(9,11)(13,16)(14,20)(15,23)(17,25)(18,26)(19,27)(21,28)(22,24) involution — undirected(6,10)(9,11)(13,15,18,17)(14,21,22,19)(16,25,26,23)(20,27,24,28)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.