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