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