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