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