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