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