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