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)(15,24)(17,26)(20,27)(22,25)(5,6)(7,10)(8,12)(9,11)(13,14)(15,17)(16,21)(18,23)(19,28)(20,25)(22,27)(24,26) involution — undirected(1,2,3,4)(13,15,16,22,18,24,19,25)(14,20,28,26,23,27,21,17)(5,7,9,8)(6,10,11,12)(13,16,18,19)(14,21,23,28)(15,25,24,22)(17,20,26,27)(5,8,9,7)(6,10,11,12)(13,17,19,27,18,26,16,20)(14,22,21,15,23,25,28,24)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.