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