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