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