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