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