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