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