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