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