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