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