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