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