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)(13,14)(15,19)(16,17)(18,20)(21,22)(23,25)(24,26)(27,28) involution — undirected(5,6,8,10)(7,9,11,12)(13,14,17,16)(15,19,20,18)(21,23,27,26)(22,24,28,25)(7,11)(9,12)(14,16)(18,19)(21,24,27,25)(22,23,28,26)(1,2,3,4)(5,6)(7,9)(8,10)(11,12)(13,15)(14,18)(16,19)(17,20)(21,25,27,24)(22,23,28,26)(5,7,8,11)(6,9,10,12)(13,16,17,14)(15,19,20,18)(21,26,27,23)(22,24,28,25)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.