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