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