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