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