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