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