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