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