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