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