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