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