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