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