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