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