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