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