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