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