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