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