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