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