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