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