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