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