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