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