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