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