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