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