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