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