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