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