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