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)(15,21)(16,25)(17,27)(18,20)(19,24)(22,26)(23,28)(1,2)(3,4)(5,7)(6,10)(8,11)(9,12)(13,15,17,24,18,23,26,16)(14,19,22,21,20,25,27,28)(6,11)(7,12)(14,20)(15,23)(16,24)(22,27) involution — undirected(2,4)(5,8,9,10)(6,12,11,7)(14,20)(19,25)(21,28)(22,27)(13,16,26,23,18,24,17,15)(14,21,27,19,20,28,22,25)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.