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