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