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