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