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