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