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