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